What Does Earth Look Like From Mars?

Curiosity is inside Gale Crater far to the east of the planet’s most prominent telescopic feature Syrtis Major. Credit: NASA/ESA/ Hubble

Now that Curiosity’s safe and secure on the Red Planet and snapping photos of everything in sight, I hope it focuses its cameras on Earth sometime soon.

The rover sits inside the 96-mile-wide Gale Crater in Mars’ eastern hemisphere just 5.4 degrees south of the equator. I was curious what the sky looks from Curiosity’s location and fired up Stellarium to see.

It didn’t take long to find Earth, low in the northeastern sky in morning twilight not far from the planet Venus.

Seen from Gale Crater on Mars, Earth is a brilliant blue “star” in the constellation Pisces on August 10. Not far below shine the planet Venus. The view shows the sky facing east about 45 minutes before Martian sunrise. Maps created with Stellarium

Since Earth is an “inner planet” from Mars’ perspective, the same way Venus and Mercury are inner planets for us, it never strays too far from the sun and goes through phases just like the moon and other inner planets. Curiosity will see Earth best during morning and evening twilight. At Mars current distance from Earth of 154 million miles, our planet shines at magnitude -1.4 or nearly same as Sirius, the brightest star in the sky.

To the eye, Earth would shine a pale ocean water blue. Venus would still be the brightest planet (magnitude -3.0) but distinctly dimmer than when viewed from Earth, because it’s farther from Mars than it is from our planet.

Earth and moon seen through binoculars from Curiosity’s landing site this morning.

According to my calculation, the moon would be slightly less than one arc minute from Earth and probably not visible as a separate point of light with the naked eye. However, you could easily see it directly below Earth through a pair of binoculars. The two would appear as a beautiful double planet!

The moon is much darker than Earth and would only shine at magnitude 2.5, about the same brightness as one of the Big Dipper stars. Through a small telescope magnifying around 60x Earth would appear as a tiny gibbous moon or a little more than 3/4 full.

More sky wonders await Curiosity’s cameras. Mars’ two moons cycle through the sky just like our moon.

Mars’ moon Phobos joins Earth and Venus shortly before sunrise on the morning of August 12.

Phobos, the larger, is 14 miles wide and orbits only 3,700 miles from Mars’ surface. It’s so close that it moves around Mars faster than the planet rotates. Instead of rising in the east and setting in the west, Phobos rises in the west and sets in the east. Nuts, right? It moves so fast it crosses the entire sky in just four hours and 15 minutes. If you could be there in person, you’d see it move in real time like a very slow satellite.

While Phobos is one of the darkest, least reflective bodies in the solar system, its proximity to the planet means it’s brighter than you’d expect, easily outshining Earth and Venus at magnitude -5 at midmonth. Wait a minute – that’s brighter than Venus is from Earth!

The smaller moon Deimosis about 7 miles wide and orbits far enough from the planet to rise in the east and set in the west like our moon does. Things really get fun later this month on the morning of 31st. That’s when Earth, Venus, Phobos and Deimos are all together in the eastern sky before sunrise. Wouldn’t it be cool if NASA pointed one of the high-resolution cameras for an awesome family portrait?

Mars’ north polar axis points toward Deneb and the Northern Cross which are part of the larger Summer Triangle. This view shows the sky from mid-northern latitudes on Mars. From roughly 10 degrees north of the Martian equator to the north pole, Deneb never sets.

One last tidbit. Mars’ axis is tipped 25.2 degrees, nearly the same as Earth’s 23.5 degrees. That’s why both planet’s have seasons. Despite similar inclinations, Mars’ axis points to a different direction in the Martian sky. Earth’s north polar axis points to the venerable North Star in the Little Dipper. Mars’ “north star” is close to Deneb, the bright star that marks the head of the Northern Cross or constellation Cygnus. Mars’ southern polestar is near the naked eye star Kappa Velorum.

It’s fun and fascinating to imagine how the planets and stars look on other worlds, especially the one we’re exploring with robotic eyes at this very moment. Seeing Earth from far away allows us to put our planet in perspective – we’re a point of light dancing among the stars just like all the other planets.

Earth – that tiny point of light near the top – photographed by the Spirit Rover on Mars. Credit: NASA

Hi Mike,
I’m sure Curiosity would be able to photograph the Earth and the Martian moons. Venus is very low so it might get cut off or lost in glare. I hope they’ll decide to make those pictures. Your comment reminded me I’d forgotten to include a shot of Earth made by the Spirit Rover. I just updated the blog now with the picture.

Mike,
Blue is an uncommon color among stars seen with the naked eye that’s for sure. Those cameras looks pretty good on Curiosity though I wonder how well it would register the color. If the exposure was made at the right time – so as to not overexpose Earth and blow out the color – I suspect it could be done.

Alex,
Since 71% of Earth is covered in water, it will actually be much bluer than green. The rest – 29% – is covered by deserts, barren and snow-covered mountains, the polar regions and … green plants, a percentage of which turn brown in the fall.

Another great post! Perhaps for a future topic, you could talk about possible Martian calendars. I know talking about Sol 1, Sol 2, etc. gets confusing after a while. When do Martian children celebrate the first day of fall and go back to school? Also, do the Martians in the Southern Hemisphere have a pole star?

Hiya, great post! I especcially enjoyed the Deimos information, being a bit of a space geek myself! Helped with my research project an awful lot, finally I have found an accurate and interesting, reliable source! Could have done with you twenty years ago doing my physics homework! Many thanks, Lilac India Blue

Hi Bob,
thanks for a great post! It’s interesting to see that most of the night sky on Mars looks pretty similar to our view, except for some decisive new specks. I guess, as Curiosity is not powered by solar panels but by another power source that allows it to operate even through the night there, it should be posible to “lift its eyes” to the night sky and send us some nice pictures of the stars and planets seen from Mars.

Lovely idea to combine the Stellarium simulation with a photo from Curiosity’s surroundings, thanks again
greetings
Stephan

Great to see NASA finally using a stable arresting and landing platform. I never understood the inherently unstable landers of old. But, I’m still confused by the multiple cable release system. There are so many better configurations that incorporate KISS theory.

Hi Cyan,
At Mars current distance from Earth, the two are close enough together in Mars’ sky to need binoculars to separate. And while the Earth-moon image is based on real data, it’s still only a simulation.

Yes, that fake image purported to be an actual photo from Mars has been going around the Internet. Funny how the perpetrator forgot to crop out the “northeast” direction at the bottom of what it really is – a scene created with star-charting software!

Of course most of the time the Moon would be very far from the Earth in terms of visible Earth radii – up to 240,000 / 8,000 = 30 Earth radii. It would be unusual to see both Earth and Moon in the same high-power telescope field of view. Once in a blue moon however, or blue Deimos, the Moon would pass directly in front of the Earth, in fact, when we on Earth experience an occultation of Mars by the Moon.

Hi D R,
Thanks for your comment but I beg to differ. 30 Earth radii = 15 Earth diameters. When Curiosity landed, Mars was about 6″ in diameter seen from Earth. Earth from Mars would have been about twice as big or 12″ across. 12 x 15 diameters = 180″ or 3 arc minutes. That’s about how far the moon would appear from Earth – a beautiful, close “double planet” in binoculars. Three arc minutes is still a small enough separation to easily fit inside a high-power eyepiece field of view. I’d be able to fit the moon and Earth with considerable room to spare in my 4.8 mm Nagler (357x). The only difficulty would be toting my scope to Mars in the first place! You are correct that when the moon lies up exactly between Earth and Mars some areas of Earth will experience a Mars occultation.

Hi Eddy,
Thank you very much! The closer something is, in general brighter or bigger it looks in the sky, but not always. Venus is still brighter than Earth from Mars because it’s completely cloud covered and so reflects more sunlight than our planet does.

Dear sir, I am very interested to Know the if any life in any other Planet or other salary system or other Galaxy , Plz invent soon within 50 yrs Becoz, I am now 30 yrs, I have to see the life in other Planets
Wat a beautiful Creature …………………………………………………
Plz update Any latest discovery…………………..

Thanks Ray. Venus is generally brighter than Earth from Mars because its perpetual cloud cover makes it an excellent reflector of light. However, Earth around greatest brilliancy can be brighter than Venus if Venus is a very thin crescent at the same time.

This makes me think about the tiny egos we carry with us… just to show others that we are superior to them as we are having more colored papers in our pockets….when the whole earth is looking like a dot… what is the status of a man?

What I’m really courious about, how do the familiar constellations viewed from earth, the Great Bear, Orion’s belt etc because of the great distances millions of miles, do the constellations form the same shape, viewed from Mars, surely the Great Bear would look different viewed from Mars.

Colm,
Wonderful question. The constellations are no different on Mars than seen from Earth because the stars in all of them are at vast distances compared to planets’ distances from the sun. Consider that Mars’ average distance from the sun is 141 million miles or about 48 million miles farther away than Earth. The nearest star system, Alpha Centauri lies some 26 trillion miles away. 48 million miles is only 0.18% of 26 trillion, which translates to to a tiny fraction of a degree change in position in the sky seen from Mars vs. Earth. Since most naked eye stars are much farther away, this number would be much smaller.

Many thanks Astrobob for your reply, I hope to see more Martian night sky pictures from Curiosity, particularly the familiar constellations like Orion etc, it would be interesting to see the view from Mars.
Just off topic, we’ll probably never get a view from Venus, it hangs like a jewel in the morning sky, but below it’s thick cloud cover and dense atmosphere lies a hellish environment with a surface temperature of 400degree, unlike Mars, Venus is completely out of our league.

Sandile,
NASA has many resources available to the public – dozens of websites on Mars, Saturn, meteors, the space station and countless other topics. All free and all available 24/7. Just type in the word ‘NASA’ and any topic about astronomy or astro-biology and you’ll see LOTS!

Hi Becca,
Jupiter would look about one magnitude brighter than it does from Earth when Mars and Jupiter are at their closest. Bright than at Earth but not quite equal to Venus. Because Jupiter is still an outer planet as seen from Mars, it would never show a crescent phase.